混凝水处理法应用现状及强化措施探讨

首先分析了混凝效果影响因素,总结了传统混凝技术在处理低温低浊水、去除藻类、含油废水中磷去除等方面的特点及其存在问题.同时,介绍了新型的混凝处理技术,如污泥回流工艺、混凝—气浮法、微生物絮凝剂、钛盐混凝剂、基于果皮类的混凝技术的应用现状,并归纳其优缺点.最后针对不同废水特性,探讨相应的混凝强化技术,如污泥回用强化混凝处理...     

分析无机絮凝剂混凝机理中的力化学因素

以混凝机理为基础,建立了无机絮凝剂的混凝物理模型。通过混凝物理模型与无机絮凝剂的双电层压缩机理相结合,研究无机絮凝剂和投加时的稀释比例不同产生的效果,指出无机絮凝剂的混凝机理中存在流体力化学效应。     

生物絮凝剂法在废水处理中的应用研究

混凝法是废水处理中最常用的重要方法,而絮凝剂的性质、种类的好坏是关系到混凝处理效果的关键因素。本文首先对生物絮凝剂的絮凝机理,影响生物絮凝剂絮凝能力的因素以及可被生物絮凝剂絮凝的物质进行了介绍;然后对其在废水处理中的应用作为重要叙述;最后对生物絮凝剂的发展前景作了简要概括。     

无机高分子絮凝剂混凝吸附性能的比较研究

比较了无机高分子絮凝剂聚合硫酸铁(PFS)、聚合氯化铝(PAC)和聚氯硫酸铁(PFCS)在废水处理中的混凝吸附性能，并对絮凝剂的混凝机理进行了初步探讨。研究结果表明，在使用量相同的情况下，聚铁的絮凝性能明显优于聚铝，经改性后的PFCS使用的pH范围更宽，混凝除浊效果更好。在选定的实验条件下，经砂滤、絮凝、活性炭吸附处理后，水样中CODCr,浊度、色度和SS的去除率均在80％以上，出水可达到国家污水综合排放标准。     

藻类混凝过程的影响因素探讨

应对"水华"突发事件,最经济有效的方法之一是混凝沉淀除藻法,详细讨论了影响藻类混凝效果的因素,如混凝剂的种类、藻类生长周期、特性有机物(EOM、NOM)、预氧化作用等,通过对这些影响因素的研究,为提高藻类去除率和降低混凝剂的用量提供了参考,并且为藻类混凝去除方法的选择及开发提供一定的指导意义。     

微生物絮凝剂-阳离子型无机微粒体系的混凝脱色研究

从啤酒厂废酵母直接提取微生物絮凝剂,与水合氧化铁微颗粒体系集成应用于混凝脱色,其脱色效果与无机微颗粒体系的电荷密度、微生物絮凝剂剂量有关,提出无机微颗粒与染料集合体的"剩余电荷"的概念解释微生物絮凝剂-阳离子型无机微粒体系的混凝机理.结果显示微生物絮凝剂-水合氧化铁微粒体系混凝脱色在试验范围内均有显著的协同效应,直接黄最高脱色率达到95.5%,分别比单独使用水合氧化铁微粒和微生物絮凝剂提高33.6%和82.6%.     

聚硅硫酸铁的制备及性能研究

以硅酸钠、硫酸铁为原料制备了无机高分子絮凝剂聚硅硫酸铁(PFSS)，确定了最佳制备条件，并实验了它的混凝除浊性能及印染废水COD的去除率，结果表明：PFSS具有良好的混凝除浊性能，印染废水COD的去除率比较高，是一种比PFS性能更优良的絮凝剂。     

预氧化混凝去除原水中铜绿微囊藻及同步控制消毒副产物生成

湘江流域长沙段夏季藻类频繁暴发，然而常规混凝工艺对原水中的藻类及其生成的消毒副产物前驱体的去除效果欠佳，对供水安全造成一定的威胁。预氧化混凝法由于除藻效果较好，而且不需在水处理工艺流程中增设处理构筑物，具有很好的应用前景。文中以长沙市水厂藻类暴发时的主要藻种——铜绿微囊藻为例，探讨了预氧化混凝法的除藻效果和消毒副产物控制情况。结果表明，单独混凝时，10 mg/L聚合硫酸铝(PAS)的除藻率为92.7%,分别使用K₂FeO₄、ClO₂、KMnO₄、O₃或NaClO对藻类进行预氧化处理后再混凝，除藻率最高提升至100.0%、99.1%、98.2%、98.2%或96.4%。0.2 mg/L K₂FeO₄或KMnO₄使溶解性有机碳(DOC)的去除率较单独混凝分别提高了12.3%和19.4%,而同等用量的ClO₂、O₃和NaClO则造成藻液中的DOC水平增加。质量浓度≤1.0 m...     

藻类有机物对混凝的影响研究进展

藻类有机物一直都是水处理工艺有效运行的威胁,近五年来藻类有机物组成性质上的研究成果主要体现在对各类藻种的有机物的荧光分析,荧光的平行分解,胞外有机物中不同组分的划分,分子量分析和等电位聚焦,以及官能团性质的表征。在此基础上,影响混凝的藻类有机物成分,胞内外有机物影响混凝的区别,以及蛋白质性质与混凝效果的关系等研究也取得了进展。近几年还有不少学者对预氧化的程度以及混凝剂的优化进行了探究,其研究成果提出了有效地降低藻类有机物对混凝的影响的措施。     

硫酸铝催化合成双氰胺-甲醛絮凝剂的研究

以双氰胺、甲醛为主要原料，以硫酸铝为催化剂并引入添加剂合成了双氰胺-甲醛树脂高效脱色阳离子有机絮凝剂-双氰胺-甲醛树脂。探讨了甲醛用量、催化剂用量、反应温度、反应时间、添加剂用量对双氰胺-甲醛树脂产品混凝脱色性能的影响，并对染料废水进行了混凝脱色试验。该絮凝剂较其他絮凝产品在污水处理、降低色度、悬浮物和COD去除等方面效果显著。     

In Silico Analysis of Correlations between Protein Disorder and Post-Translational Modifications in Algae

Recent proteome analyses have reported that intrinsically disordered regions (IDRs) of proteins play important roles in biological processes. In higher plants whose genomes have been sequenced, the correlation between IDRs and post-translational modifications (PTMs) has been reported. The genomes of various eukaryotic algae as common ancestors of plants have also been sequenced. However, no analysis of the relationship to protein properties such as structure and PTMs in algae has been reported. Here, we describe correlations between IDR content and the number of PTM sites for phosphorylation, glycosylation, and ubiquitination, and between IDR content and regions rich in proline, glutamic acid, serine, and threonine (PEST) and transmembrane helices in the sequences of 20 algae proteomes. Phosphorylation, O-glycosylation, ubiquitination, and PEST preferentially occurred in disordered regions. In contrast, transmembrane helices were favored in ordered regions. N-glycosylation tended to occur in ordered regions in most of the studied algae; however, it correlated positively with disordered protein content in diatoms. Additionally, we observed that disordered protein content and the number of PTM sites were significantly increased in the species-specific protein clusters compared to common protein clusters among the algae. Moreover, there were specific relationships between IDRs and PTMs among the algae from different groups.     

高锰酸钾预氧化耦合混凝工艺对藻类及类蛋白物质的控制效果

为降低水中藻类及有机物含量,利用三维荧光和藻类分析仪,研究KMnO4强化混凝对藻类和类蛋白物质的去除,探索KMnO4投加量和反应时间的影响。研究表明:KMnO4对藻类和藻蓝蛋白的去除率仅为38.46%和15%,KMnO4耦合混凝对两者的去除率分别为86%和75%。铜绿微囊藻中主要荧光组分为可溶性微生物产物和小分子类蛋白,KMnO4耦合混凝对其的去除率为32.77%。结果表明,1 mg/L KMnO4预氧化30 min后投加混凝剂,能最大程度地去除藻类及藻蓝蛋白,但并不能较好地去除类蛋白物质。     

超滤膜组合工艺处理高藻水库水试验研究

进行中试试验考察了污泥回流—超滤组合工艺处理高藻期水库水的除污染效能和膜污染状况。试验结果表明,组合工艺对浊度、CODMn、UV254、藻类的去除效果要优于水厂常规处理工艺;污泥回流预处理可以使膜运行稳定,膜前压力在较长时间内保持恒定;该组合工艺可以作为高藻期水库水处理的一种有效方法。     

The distribution of sterols in algae

Available analytical techniques are now sufficient for the separation and identification of sterols from complex mixtures in plants. Gas and thin layer chromatography and mass spectroscopy in particular, have been used to resolve some of the confusion concerning the sterol composition of algae. Red algae (Rhodophyta) contain primarily cholesterol, although several species contain large amounts of desmosterol, and one species contains primarily 22-dehydrocholesterol. Only a few Rhodophyta contain traces of C-28 and C-29 sterols. Fucosterol is the dominant sterol of brown algae (Phaeophyta), apparently the major sterol of every species examined. Most Phaeophyta also contain traces of cholesterol and biosynthetic precursors of fucosterol. The sterols of green algae (Chlorophyta) are much more varied and complex than those of other groups of algae. Whereas the Phaeophyta and Rhodophyta contain one primary sterol, many of the Chlorophyta contain a complex mixture of sterols such as occurs in higher plants. The Chlorophyta contain such sterols as chondrillasterol, poriferasterol, 28-isofucosterol, ergosterol, cholesterol and others. Sterol composition may be of value in the systematics of plants such as the Chlorophyta. Recently (for the first time) complex mixtures of sterols have been isolated in very small amounts in the blue-green algae (Cyanophyta). Available data on the sterols of other groups of algae are insufficient for making useful comparisons. One of 12 papers to be published from the “Sterol Symposium” presented at the AOCS Meeting, New Orleans, April 1970. Scientific Article No. A2606, Contribution No. 4331 of the Maryland Agricultural Experiment Station.     

硫酸铜灭藻影响因素的试验研究

目的通过对硫酸铜灭藻影响因素的试验研究,确定出硫酸铜灭藻的最佳工况条件.方法以叶绿素a法作为检测方法,通过烧杯试验,确定处理含藻水的最佳硫酸铜投加量、接触反应时间、pH等参数.结果硫酸铜最佳投加量为1.5 mg/L;硫酸铜适宜的接触反应时间为8～12 h;pH值6.6左右时,硫酸铜藻类去除率较高,pH值＞9时,藻类去除率显著降低.结论 pH值对硫酸铜灭藻效果的影响较大;温度对硫酸铜灭藻有一定的影响;水中还原物质浓度对硫酸铜灭藻影响较小;藻类浓度不同对硫酸铜灭藻效果有一定的影响.     

Phospholipids of New Zealand Edible Brown Algae

Edible brown algae have attracted interest as a source of beneficial allenic carotenoid fucoxanthin, and glyco‐ and phospholipids enriched in polyunsaturated fatty acids. Unlike green algae, brown algae contain no or little phosphatidylserine, possessing an unusual aminophospholipid, phosphatidyl‐O‐[N‐(2‐hydroxyethyl) glycine], PHEG, instead. When our routinely used technique of ³¹P‐NMR analysis of phospholipids was applied to the samples of edible New Zealand brown algae, a number of signals corresponding to unidentified phosphorus‐containing compounds were observed in total lipids. NI (negative ion) ESI QToF MS spectra confirmed the presence of more familiar phospholipids, and also suggested the presence of PHEG or its isomers. The structure of PHEG was confirmed by comparison with a synthetic standard. An unusual MS fragmentation pattern that was also observed prompted us to synthesise a number of possible candidates, and was found to follow that of phosphatidylhydroxyethyl methylcarbamate, likely an extraction artefact. An unexpected outcome was the finding of ceramidephosphoinositol that has not been reported previously as occurring in brown algae. An uncommon arsenic‐containing phospholipid has also been observed and quantified, and its TLC behaviour studied, along with that of the newly synthesised lipids.     

Comparative study of the extraction methods for recovery of carotenoids from algae: extraction kinetics and effect of different extraction parameters

Carotenoid extraction from algae is currently under intensive research due to the increased demand for naturally occurring compounds, which are especially rich in biologically active isomers. Furthermore, natural carotenoids exhibit greater stability than synthetic ones. Conventional liquid extraction suffers from several drawbacks, such as use of high amounts of solvent, and several extraction steps. In this work carotenoid extraction from algae using different methods, such as microwave and ultrasound assisted extraction as well as pressurized liquid extraction and extraction with supercritical CO₂ and ethane, is summarized together with modelling of extraction kinetics. In addition carotenoid availability, algae pretreatment, stability of extracts, their antioxidative and antimicrobial activities as well as downstream processing and storage of algae extracts have been reviewed. As a conclusion it can be stated that carotenoid extraction is complex, demanding optimization of the carotenoid yield and antioxidative stability, which are often inversely proportional. © 2014 Society of Chemical Industry     

Advances and Challenges on Algae Harvesting and Drying

Biodiesel production from algae offers a promising prospect for practical applications among the still developing biofuel technologies. The fact that algae are capable of producing much more yield provides an edge over other types of biofuel. Though algal biofuel research is still developing and its practical application is yet to be ascertained, promising work on laboratory- and pilot-scale algae harvesting systems has been extensively reported. Because algae harvesting and drying are vital elements in biofuel production, recent advances on various algae harvesting, dewatering, and drying technologies are reviewed and discussed. Challenges and prospects of algae harvesting and drying are also outlined.     

Enzyme-Assisted Extraction of Alginate from Beach Wrack Fucus vesiculosus

Beach wrack constitutes an unutilized, abundant renewable source of marine macro algae being rich in valuable biopolymers. This work investigates the revalorization of the brown algae Fucus vesiculosus collected from beach wrack as a source of alginate, the main polysaccharide in brown algae which constitutes a potential ingredient for the development of biopolymer films. Enzyme-assisted extraction has been investigated for cell disruption with commercial cellulase blends and proteases. The effect of enzyme type, enzyme activity, and extraction time on alginate yields, molecular weight distribution, functional groups, and purity has been studied.     

A novel on‐line optical method for algae measurement

In recent years, algal blooms have occurred worldwide, and algae‐rich water often has adverse effects on water production. The technique of algae measurement is a critical issue for adjusting water treatment processes according to the numbers of algae cells. The algae particles in the water are generally 2–200 µm in size with only a few smaller than 2 µm. The traditional algae measuring method is by visual observation with an optical microscope. However, traditional visual observation often needs 48 h fixing time, which makes the measurement results lag behind the needs of water production. To solve the problem, this study employed on‐line optical devices to improve the efficiency and accuracy of algae measurement. A photometric dispersion analyzer (PDA) and particle counting analyzer (PCA) were jointly utilized to monitor on‐line the algae concentration in natural water. Algae cells can be classified by different sizes. It was found that there was good correlation between R²_PDA and total algae counts in water. The PCA could quantitatively characterize the algae counts and species distribution of dominant algae species in real water. PDA and PCA could be used jointly to define on‐line the characteristics of real water containing mixed algae. Copyright © 2010 Society of Chemical Industry